Shuttle envelope feeder with suction cup assist

ABSTRACT

An envelope feeder for removing envelopes from an envelope stack. The envelope feeder comprises a shuttle plate and a suction cup assembly. The shuttle plate translates between a position under the envelope stack and another position partially remote from the envelope stack. The shuttle plate includes an orifice passing through its surface and an envelope gripping mechanism in connection with a vacuum valve. The suction cup assembly has a suction cup connected to a hollow rod that is in connection with another vacuum valve. An actuator engages the suction cup and moves the suction cup between an extended position and a retracted position. The suction cup attaches to an envelope at the bottom of the envelope stack when it is in the extended position, and pulls the envelope toward the shuttle plate as it moves to the retracted position. Then the envelope gripping mechanism retains the envelope, allowing the shuttle plate to remove the envelope from the envelope stack.

TECHNICAL FIELD

This invention generally relates to machines that operate at a very highspeed to insert sheets of paper or other items into envelopes. Moreparticularly, it relates to a shuttle envelope feeder that transportsthe envelopes to be inserted.

BACKGROUND ART

Machines for automatically inserting items such as sheets of paper intoenvelopes are known in the art. A state-of-the-art mail insertingmachine such as the Pitney Bowes Flowmaster™ FX14 can perform 12,000insertions per hour when properly maintained and adjusted.

A typical high-speed inserting machine comprises several modules. Afirst module transports an elongate horizontal queue of envelopes to anenvelope stack. An envelope feeder located at the bottom of the envelopestack delivers the envelopes one by one to an envelope insertionstation. A second module delivers individual groups of stacked sheets tothe envelope insertion station. A third module, the envelope insertionstation, includes clamps carried by an elongate sprocket chain thatsequentially receives envelopes from the envelope feeder and pulls thempast an envelope flap-opening structure and a sheet inserting structurewhere the envelopes are opened and inserted with stacked sheets. Theenvelopes are then pulled past an envelope closing structure and anenvelope sealing structure before been ejected to a collection station.envelope closing structure and an envelope sealing structure before beenejected to a collection station.

FIG. 1 schematically shows an arrangement of a prior art envelopefeeder. The envelope feeder comprises a shuttle plate 150 that movesback and forth (direction shown as doted arrow line 152) to transportenvelopes 140 to be grasped by clamps 190 on an elongate sprocket chain160 of the insertion station. The shuttle plate has a recessed area inwhich a vacuum gripping mechanism 180 is arranged. The negative pressureform the vacuum gripping mechanism 180 pulls the part of the envelopedirectly above the recessed area toward the recessed area so as totemporarily secure the envelope to the upper surface of the shuttleplate. When the shuttle moves toward the sprocket chain 160, a stripperbar 170 located above the recessed area separates the secured bottomenvelope from the envelope stack and allows it to move forward with theshuttle.

The vacuum envelope feeder of the above arrangement works well whenenvelopes are substantially flat. If, however, some of the envelopes aresignificantly curled or bent, the shuttle vacuum may not have sufficientsuction to pull down these envelopes, causing a failure in the shuttlefeed.

Some methods have been proposed in order to solve the above problem. Oneis to add pressure to the top of the envelope stack to help flatten theenvelopes. This method is somewhat ineffective, because an improperlyapplied stack pressure can also cause a failure in the shuttle feed ormultiple envelope feedings.

Another method uses a thumper to add stack pressure when the shuttlevacuum is turned on. When the shuttle moves forward, the thumperretracts and the shuttle vacuum holds the curled envelope. Thedisadvantages of this method are that the thumper disturbs the stack andthe flow of envelopes from the envelope transport module, and itrequires constant mechanical adjustment.

What is needed is a vacuum shuttle feeder that is capable of feedingcurled envelopes without failure. Preferably, the operation of suchfeeder will not interfere with existing configuration of the envelopestack or envelope flow. In addition, the feeder should be operative overa wide range of envelope dimensions.

SUMMARY OF THE INVENTION

The invention provides an envelope feeder in an envelope insertionmachine for removing envelopes from an envelope stack. The envelopefeeder comprises a shuttle plate and a suction cup assembly.

The shuttle plate is operable between a first position under theenvelope stack and a second position at least partially remote from theenvelope stack. The shuttle plate has an orifice passing through itsupper surface, and an envelope gripping mechanism that is incommunication with a shuttle vacuum valve.

The suction cup assembly comprises a suction cup that has an upper rimand a lower neck with an opening formed therein, the opening isconnected to a hollow rod. The rod, in turn, is in communication with asuction cup vacuum valve. An actuator engages the suction cup and movesthe suction cup between an extended position that passes through theorifice in the shuttle plate to a retracted position that the upper rimof the suction cup is at least flush with the upper surface of theshuttle plate.

The suction cup vacuum valve is activated at least when the suction cupis in the extended position so that the suction cup attaches to anenvelope at the bottom of the envelope stack. The suction cup pulls theenvelope toward the upper surface of the shuttle plate as the actuatormoves from the extended position to the retracted position.

The shuttle vacuum valve is activated at least when the envelope ispulled toward the upper surface of the shuttle plate. By doing so, theenvelope is retained by the envelope gripping mechanism, allowing theshuttle plate to remove the envelope from the envelope stack as theshuttle plate moves to its second position.

The invention further provides a method for an above-described envelopefeeder in an envelope insertion machine to remove an envelope from anenvelope stack. The method comprising the steps of: placing the shuttleplate in the first position, moving the suction cup between theretracted position that is at least flush with the upper surface of theshuttle plate and the extended position that is in contact with anenvelope at the bottom of the envelope stack, and controlling the airpressure within the suction cup so that the suction cup has a lower airpressure than the ambient air pressure when the suction cup is in theextended position and while it moves from the extended position to theretracted position.

In accordance with the method, the envelope at the bottom of theenvelope stack is pulled down toward the upper surface of the shuttleplate so as to facilitate the acquisition of said envelope by theenvelope gripping mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the inventionwill become apparent from a consideration of the subsequent detaileddescription presented in connection with accompanying drawings, inwhich:

FIG. 1 is a schematic illustration of a prior art shuttle feeder part ofan envelope insertion station.

FIG. 2A is a schematic top view of a shuttle envelope feeder with vacuumsuction assist, according to a first embodiment of the invention.

FIG. 2B is a schematic cross-sectional view of a shuttle envelope feederwith vacuum suction assist, taken along line 2B in FIG. 2A, according tothe first embodiment of the invention.

FIG. 3 is a block diagram of the shuttle envelope feeder with vacuumsuction cup assist, including valves and controlling mechanism,according to the first embodiment of the invention.

FIG. 4 is a three-dimensional view of the shuttle envelope feeder,according to the first embodiment of the invention.

FIG. 5 is a three-dimensional view of the shuttle envelope feeder,according to a second embodiment of the invention.

FIG. 6 is a three-dimensional view of the shuttle envelope feeder,according to a third embodiment of the invention.

FIG. 7 is a block diagram of the shuttle envelope feeder with vacuumsuction cup assist, including valves and controlling mechanism,according to the third embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 2A, a shuttle envelope feeder 200, according to thepresent invention comprises a shuttle plate 150 operable between a firstposition under an envelope stack and a second position that is at leastpartially remote from the envelope stack. The shuttle plate 150 has asurface 252 dimensioned for receipt of an envelope. The surface 252 hasa leading edge 254. The shuttle plate 150 has an orifice 240 passingthrough the surface 252. The shuttle plate 150 further has a recessedarea 280 formed in its surface 252 in proximity to the orifice 240 andextending at one end to the leading edge 254 of the surface 252. Therecessed area 280 has at least one orifice 181 passing therethrough andin communication with a shuttle vacuum valve 256 (seen in FIG. 3) toform a vacuum gripping mechanism 180.

Referring now to FIG. 2B, the vacuum envelope feeder further comprises asuction cup 230 having an upper rim 232 and a lower neck 234. The lowerneck 234 has an opening formed therein, which is connected to a hollowrod 233, the rod, in turn, is in communication with a suction cup vacuumvalve 238 (seen in FIG. 3).

The suction cup 230 is thus in cooperative engagement with an actuatoror air cylinder 236, which, in turn, is in communication with an aircylinder valve 262 (seen in FIG. 3). The actuator 236 moves the rod 233and thus the suction cup 230 between an extended position that passesthe suction cup through the orifice 240 in the shuttle plate 150 and aretracted position so that the suction cup resides inside the orificeand the upper rim 232 of the suction cup 230 is at least flush with thesurface 252. The orifice 240 is dimensioned so that the suction cup 230and/or the hollow rod 233 is not in contact with the orifice and not inobstruction with the movement of the shuttle plate.

Referring further to FIG. 3, the vacuum envelope feeder also comprises acontrolling mechanism including a computer 300 (or other programmablelogical device) that coordinates an input/output control module 310 bymonitoring the shuttle position via an up/down counter 320 incommunication with an encoder 330 equipped with a position sensor 331via a position circuit. The position circuit may consist of an up/downcounter 320 in communication with an encoder 330 equipped with aposition sensor 331 or an input port that allows the computer todirectly read position of the shuttle plate from an absolute encoder orpositional resolver.

With the shuttle plate 150 at the first position and the trailing edgeof the previous envelope off of the suction cup 230, the actuator 236moves the cup 230 toward the extended position and the suction cupvacuum valve 238 is activated (vacuum ON). Once the suction cup 230reaches the extended position, a small time delay is used to insure thatthe suction cup 230 attaches to an envelope at the bottom of theenvelope stack. The actuator then pulls the suction cup 230 toward theretracted position.

Once the suction cup 230 reaches the retracted position, the shuttlevacuum valve 256 is activated to allow the envelope gripping mechanism180 to acquire the envelope. The suction cup vacuum valve can bedeactivated (turned OFF) immediately after envelope is acquired. Theshuttle plate 150 then moves toward the second position with theenvelope going under a stripper bar 170 so that it is separated from theremaining envelopes in the envelope stack. After clamps 190 (see FIG. 1)on the mail insertion station have grasped the envelope, the shuttlefeeder returns to its initial position, ready to acquire the nextenvelope.

The computer 300 stores parameters such as the real-time shuttleposition acquired via a position circuit with an position encoder orresolver 330 having a position sensor 331, envelope width, the distanceD between the leading edge 254 of the shuttle plate and the center ofthe suction cup 230, air valve latencies, air cylinder latencies andsystem latencies. Based on the parameters pre-stored in the computer andacquired by the computer, the computer calculates a time sequence foractuating the suction cup and activating/deactivating the suction cupvacuum valve for the input/output control module 310 to coordinate theoperation of the valves. The specific computer programming andcontrolling procedures of vacuum and air valves according to suchspecific parameters is known to people of ordinary skills in the art.

First Embodiment of the Invention

In a first embodiment of the invention as shown in FIG. 4, the shuttleplate 150 comprises an orifice 240 passing through the surface 252. Theshuttle plate 150 and the actuator 236 that supports the suction cup 230are mounted rigidly on a frame 392. The frame moves from a firstposition to a second position by a rolling mechanism 394 on a horizontalbar 396. The orifice 240 is dimensioned larger than the outer dimensionof the suction cup 230 so as to allow the suction cup to reside insidethe orifice when the suction cup is in the retracted position.

Second Embodiment of the Invention

In a second embodiment of the invention as shown in FIG. 5, the shuttleplate 150 comprises an orifice 440 passing through the surface 252. Theshuttle plate 150 and the actuator 436 that supports the suction cup 430are mounted on two separate frames 392 and 498, respectively. Theshuttle plate 150 mounted on the frame 392 moves from a first positionto a second position by a rolling mechanism 394 on a horizontal bar 396.Frame 498 is stationary in relationship to the insertion station. Theorifice 440 is in an elongated shape and is dimensioned larger than theouter dimension of the suction cup 430. The suction cup 430 residesinside the orifice when it is in the retracted position, and the suctioncup is not in obstruction with the movement of the shuttle plate.

Third and Preferred Embodiment of the Invention

In a third and preferred embodiment of the invention as shown in FIG. 6,the shuttle plate 150 comprises a first orifice 240 and a second orifice440, both passing through the surface 252. The shuttle plate 150 and afirst actuator 236 that supports a first suction cup 230 are mountedrigidly on a frame 392. A second actuator 436 that supports a secondsuction cup 430 is mounted on a frame 498. Frame 392 moves from a firstposition to a second position by a rolling mechanism 394 on a horizontalbar 396. Frame 498 is stationary in relationship to the mail insertionstation.

The first orifice 240 is dimensioned larger than the outer dimension ofthe first suction cup 230 so as to allow the first suction cup to resideinside the orifice when the first suction cup is in the retractedposition. The second orifice 440 is in elongated shape and isdimensioned larger than the outer dimension of the second suction cup430. The second suction cup 430 resides inside the second orifice 440when the second suction cup is in the retracted position, and the secondsuction cup is not in obstruction with the movement of the shuttleplate.

As shown in FIG. 7, the first suction cup 230 is connected via a hollowrod to a first suction cup vacuum valve 238. A first actuator or aircylinder 236 that moves the first suction cup is in communication with afirst air cylinder valve 262. The second suction cup 430 is connectedvia a hollow rod to a second suction cup vacuum valve 438. A secondactuator or air cylinder 436 that moves the second suction cup is incommunication with a second air cylinder valve 462.

A computer 300 (or other programmable logical device) stores parameterssuch as the real-time shuttle position acquired via a up/down counter320 in communication with a position encoder 330 having a positionsensor 331, envelope width, the distance D between the leading edge 254of the shuttle plate 150 to the center of the first suction cup 230, airvalve latencies, air cylinder latencies and system latencies. Based onthe parameters pre-stored in the computer and acquired by the computer,the computer calculates a time sequence for actuating the suction cupsand activating/deactivating the suction cup vacuum valves for theinput/output control module 310′ to coordinate the operation of thevalves.

Alternative Embodiments of the Invention

The vacuum suction mechanism of present invention may be replaced byother 15 mechanisms that temporarily acquire envelope through a movingpart that is in corporation with the shuttle plate. Examples include areceiving member in place of the suction cup that is charged with staticelectrons. The static electrons attract the envelope at the bottom ofthe envelope stack when the receiving member is in close proximity ofthe envelope. Thereby temporarily secure the envelope onto the receivingmember.

In summary, the present invention relates to a shuttle envelope feederwith a vacuum suction cup assist mechanism. The present invention hasthe advantage of acquiring cupped or bent envelopes in an envelope stackin a very repeatable fashion. The suction cup controlling mechanism isseparable from the controlling mechanism of the shuttle plate. One ormore suction cups can be individually enabled or disabled according tothe conditions of the envelopes in the envelope stack.

Although the invention has been described and illustrated with respectto exemplary embodiments thereof, the foregoing and various otheradditions and omissions may be made therein without departing from thespirit and scope of the present invention.

1. An envelope feeder in an envelope insertion machine for removingenvelopes from an envelope stack, comprising: a shuttle plate operablebetween a first position under said envelope stack and a second positionat least partially remote from the envelope stack, the shuttle platehaving a surface dimensioned for receipt of an envelope, said surfacehaving a leading edge, the shuttle plate having a first orifice passingthrough said surface, the shuttle plate further having an envelopegripping mechanism extended to the leading edge and in communicationwith a shuttle vacuum valve; a first suction cup having an upper rim anda lower neck with an opening formed therein, said first openingconnecting to a first hollow rod and said first hollow rod incommunication with a first vacuum valve; a first actuator in cooperativeengagement with the first suction cup for moving the first suction cupbetween an extended position that passes through the first orifice inthe shuttle plate to a retracted position where the upper rim is atleast flush with the surface; means for activating the first vacuumvalve at least when the first suction cup is in the extended position sothat the first suction cup attaches to an envelope at the bottom of theenvelope stack and so that the first suction cup pulls said envelopetoward the surface of the shuttle plate as the first actuator moves fromthe extended position to the retracted position; and means foractivating the shuttle vacuum valve at least when said envelope ispulled toward the surface of the shuttle plate so that the envelope isretained by the envelope gripping mechanism; thereby allowing theshuttle plate to remove said envelope from the envelope stack as theshuttle plate moves to its second position.
 2. The envelope feederaccording to claim 1, wherein the first suction cup and the firstactuator are translationally stationary in relationship to the shuttleplate, and the first orifice is dimensioned so that the first suctioncup resides inside the first orifice when the suction cup is in theretracted position.
 3. The envelope feeder according to claim 1, whereinthe first suction cup and the first actuator are translationallystationary in relationship to the envelope insertion machine, and thefirst orifice is dimensioned so that the first suction cup residesinside the first orifice when the suction cup is in the retractedposition in a manner so that the first suction cup is not in obstructionwith the movement of the shuttle plate.
 4. The envelope feeder accordingto claim 1, further comprising: a second orifice passing through saidsurface of said shuttle plate; a second suction cup having an upper rimand a lower neck with an opening formed therein, said opening connectingto a second hollow rod and said second hollow rod in communication witha second vacuum valve; a second actuator in cooperative engagement withthe second suction cup for moving the second suction cup between anextended position that passes through the second orifice in the shuttleplate to a retracted position where the upper rim is at least flush withthe surface; means for activating the second vacuum valve at least whenthe second suction cup is in the extended position so that the secondsuction cup attaches to an envelope at the bottom of the envelope stackand so that the second suction cup pulls said envelope toward thesurface of the shuttle plate as the second actuator moves from theextended position to the retracted position.
 5. The envelope feederaccording to claim 4, wherein the first suction cup and the firstactuator are translationally stationary in relationship to the shuttleplate, and the first orifice is dimensioned so that the first suctioncup resides inside the first orifice when it is in the retractedposition; and the second suction cup and the second actuator aretranslationally stationary in relationship to the envelope insertionmachine, and the second orifice is dimensioned so that the secondsuction cup moves within the second orifice when it is in the retractedposition in a manner so that the second suction cup is not inobstruction with the movement of the shuttle plate.
 6. The envelopefeeder according to claim 1, wherein the means for activating the firstvacuum valve includes an input/output control module in communicationwith a programmable logical device for controllably activating the firstvacuum valve.
 7. The envelope feeder according to claim 6, furthercomprising a first air cylinder valve connected to the first actuator,said first air cylinder valve controllable by said input/output controlmodule.
 8. The envelope feeder according to claim 1, wherein the meansfor activating the shuttle vacuum valve includes an input/output controlmodule in communication with a programmable logical device forcontrollably activating the shuttle vacuum valve.
 9. The envelope feederaccording to claim 4, wherein the means for activating the second vacuumvalve includes an input/output control module in communication with aprogrammable logical device for controllably activating the secondvacuum valve.
 10. The envelope feeder according to claim 9, furthercomprising a second air cylinder valve connected to the second actuator,said second air cylinder valve controllable by said input/output controlmodule.
 11. A method for an envelope feeder in an envelope insertionmachine to remove an envelope from an envelope stack, said envelopefeeder having a suction cup operable between an extended position and aretracted position, and a shuttle plate operable between a firstposition under the envelope stack and a second position at leastpartially remote from said envelope stack, said shuttle plate having asurface dimensioned for receipt of an envelope, an orifice passingthrough the shuttle plate, and an envelope gripping mechanism incommunication with a shuttle vacuum valve, said method comprising thesteps of: placing the shuttle plate in the first position, moving thesuction cup positioned within said orifice between a retracted positionthat is at least flush with the surface of the shuttle plate and anextended position that is in contact with an envelope at the bottom ofthe envelope stack, and controlling the air pressure within the suctioncup so that the suction cup has a lower air pressure than the ambientair pressure when the suction cup is in the extended position and whileit moves from the extended position to the retracted position; wherebythe envelope at the bottom of the envelope stack is pulled down towardthe surface of the shuttle plate so as to facilitate the acquisition ofsaid envelope by the envelope gripping mechanism.
 12. A method for anenvelope feeder in an envelope insertion machine to remove an envelopefrom an envelope stack, said envelope feeder having a first suction cupoperable between an extended position and a retracted position, a secondsuction cup operable between an extended position and a retractedposition, and a shuttle plate operable between a first position underthe envelope stack and a second position at least partially remote fromsaid envelope stack, said shuttle plate having a surface dimensioned forreceipt of an envelope, a first and a second orifice each passingthrough the shuttle plate, and an envelope gripping mechanism incommunication with a shuttle vacuum valve, said method comprising thesteps of: placing the shuttle plate in the first position, moving thefirst suction cup positioned within said first orifice between aretracted position that is at least flush with the surface of theshuttle plate and an extended position that is in contact with anenvelope at the bottom of the envelope stack, and controlling the airpressure within the first suction cup so that the first suction cup hasa lower air pressure than the ambient air pressure when the firstsuction cup is in the extended position and while it moves from theextended position to the retracted position; moving the second suctioncup positioned within said second orifice between a retracted positionthat is at least flush with the surface of the shuttle plate and anextended position that is in contact with an envelope at the bottom ofthe envelope stack, and controlling the air pressure within the secondsuction cup so that the second suction cup has a lower air pressure thanthe ambient air pressure when the second suction cup is in the extendedposition and while it moves from the extended position to the retractedposition; whereby the envelope at the bottom of the envelope stack ispulled down toward the surface of the shuttle plate so as to facilitatethe acquisition of said envelope by the envelop gripping mechanism.